combs and f



A. S. cows AND F. A. BULLINGTON.

cYLiNn'ER GRINDING MACHINE.

' APPLICATION FILED .IAN,Z5,I9IT- 1,308,166. v

IN V EN TORS.

Patented July 1, 1919,- 4 SHEETS-SHEET WI TNESSES: 'w

A. B. COMBS AND F. A. BULLINGTON.

CYLINDER GRINDING MACHINE.

APPLICAIION mD1AN.2 5.1917.

1,308,166.. Y PatontedJulyl,191$).-

4 SHEETS-*SHEET 2.

WITNESSES:

AIB. comes AND F. A BULLiNGTON.

CYLINDER GRINDING MACHINE.

APPLICATION HLED MILL), 19H- Patented July 1, 1919. 4 SHEETS-SZHEET 3- I 3 3 m n? m. m |T|l I II: II H v I l m \Q m ll L .1 v v R k N & m Aux Q R\ I l o Q 1 $4 @Qk v m 1% Y b. l k. \u Q\ N .0 HvlH. 1 All I l I I m N\ 0 Q u l! l l J mm I 1 u: lv N R l I. II I l HUI I I'll 1 I] 1' u 0 v Hu II m 1 Z y ar k fi m I R x WITNESSES: Q 220% A. B. COMBS AND F. A. BULLINGTON.

CYLINDER GRINDING MACHINE. APPLICATION FILED JAN-25.1917;

Patented July 1, 1919. S

4 SHEETS-SHEET 4.

WITNESSES fa? incense.

T nsTATEs PATENT OFFICE.

. ALB RT 3. comes in FnAnKA. nunmneromor ronrnnnnyoaneon; sun nnnnmeronassmnon or ONE-HALF 0F TI-IE WHOLE RIGHT TO EARL e.

' 0F ronrnnning OREGON.

. CYLINDER-GRINDING MACHINE.

I nppllication filed January 25, 1917. Serial No.

To all whom it may concern:

Be it knownthat we, ALBERT B. CoMB's and FRANK A. BULLINGTON, citizens of the United States, residing in the cit of Portland, county of Multnomah, an State of Oregon, haveinvented 'certain new and useful Improvements in Cylinder-Grinding Machines, of which the following is a specification.

()ur invention relates to cylinder grinding articularly to a mamachines, and more chine adapted for grinding out the inside of engine cylinders, whereby to reform therein perfectly smooth anduniform inner surfaces, thus making such cylinders substantially asgood as new. Our inventionis also adapted to be mounted and adjusted for grinding the-outside of pistons, whereby to make their outer surfaces perfectly smooth and uniform, so that they willhave a perfect fit within the cylinders.

The, principal object of our invention is to provide an improved, automatic, powerdriven machine of the character referred to, which can be quickly and. accurately adjust. ed and centered for operation in a cylinder, or on a piston, and which will automatically operate a grinding element circumferentiall around the insidepf a cylinder, and throug the same longitudinally thereof, without any further attention. r

' Another object of our invention is to provide a machine of the character referred-to, in which the grinding element, in addition to having a rotating movement and a movement longitudinally of its axis'of rotation, has a variable revolving movement bodily about a center to one side of its axis of rota- ;tion, thus adapting said machine for grinding ilylinders of varioussizes with the same grin ing element, together with means for simultaneously rotating the grinding element about its axis at one speed and for revolving the same bodily about an axis to one side ofi'ts axis of rotation, at a different different and greatly reduced-speed, all from one motor, or source of power.

Another object of our invention is to provide in a machine of the character referred to, means for locking said grinding element against its bodily revolving movement with out interfering with the rotative movement Specification of Letters Patent.

Patented July 1,1919. 144,451."

about its axis,- whereby said machine can be adapted for grindin pistons. Other objects and advantages of our invention will be apparent from the following descrlptlon of one practical embodiment thereof, taken with the accompanying sheets of drawings in which- Figure 1 is allside elevation of the invention; 2 is a top plan view thereof; .Flg. 3 is an enlarged vertical sectional View of the upper end of the machine, taken on the line 3-3 of Fig.2;

F1g. at. is a horizontal sectional view, takenonthe line H of Fig. 3; I

Fig. 5 is a fragmentary, vertical, sectional.

view taken on line 5-5 of Fig. 2;

;Fig. 6 is a fragmentary,- taken on line 6-6 of Fig. 1;

top, plan view, I

Fig. 7 is a top, plan view of our machine mounted in a horizontal position with thepiston grinder applied thereto; v Fig. 8 is aside elevation thereof;

Fig. '9 is an endview at line 9- 9, Fig. 7 Fig. 10 is an end .view of'the' machine shown in Fig. 8', looking at the left hand end thereof, with apart broken away tolre duce the size of'the figure; I

Fig; 11 is a sectional view'ofa centering device for centering the cylinder grinding -ma chine' over a cylinder which is to be groundfand Fig.12is a bottom" plan view thereof. 7

Referring now detail to'thefdrawings, i Fig! 1, -C designates a fragmentary, sec;

- tional view of arcylinder on which our 'mader. An open supporting frame, or block,

*1, is mounted upon the cylinder "and cen-,

tered relative thereto, said frame comprising an upper ring 2, and a lower rin'gfl3,

bar 9. At the opposite side of said bearing.

9t! chine is mounted for regrinding'said cylin-- ring 2, of-the supporting frame; 1. I

8, to which is secured a guide i r sleeve 7, said base casting has formed thereon a bearing box 10.

Slidably mounted through said bearing sleeve 7, is a cylindrical member 11, connected at its upper end with a cylindrical portion 12, of a main top casting 32, said cylindrical portion 12, having a guide lug '13, formed thereon, and slidably connected with the guide bar 9. Secured near'the up per end around said cylindrical member 11,-

4 is 'a gear ring 14. This gear ring is secured to'said cylindrical member 11, for driving I the same, by means of a key 15, which key,

however, may be'moved downwardly in a seat'16, formed in the side of said cylindrical member 11, so as to permlt sa d gear ring 14, to turn freely on said cylindrical if member 11, as will be clearlyunderstood from Figs; land 5.

. ,drical memberl'l, is a bearing tube 17,

u Mounted eccentrically through said cylinshown in, section i'n'Fig. 5. Mounted eccentri'cally within said bearing tube 17, is a spindle, or shaft, 18, upon the upper end of which is mounted a drive pulley 19, whileat its 'lowerend said-spindle, or shaft,'18, is provided with a grinding element 20,

I which is detachable, and therefore can be exchanged for other grinding elements.- -In Figs. 1 and 5, .said bearing tube '17, is so turned within the bearing cylinder 11, that the shaft, or spindle, 18, is at an. off center fiositi'onwithin the cylindrical member 11.

y turning the bearing tube 17 ,within the cylindrical member 11, said spindle, -or

' shaft, 18; can be moved to a position concentrio with said cylindrical member 11. This I will be understood by the full-line position,

and the vdotted line position of'said spindle,'. 40

as'shown in theplan view in Fig. 6.

Said spindle 18, has a. tapered bearing member 17, Fig. '5, in the upper end of the tubular member 17, which is adapted to be raised and lowered'in said tubular member 17, by means of a screw 17", which has a headjflange 17, which fits into a notch in said tapered bearingl7 by means of which screw said tapered bearing 17, can be adjusted to, take up wear, said screw 17", screw ing into the top of the tubular member 17.

- the, swing of the spindle 18, said bearing tube 17 is provided at its upper endiwith a plate 21, provided'with a circular slot 22,

therein, adapted to receive a screw bolt 23,

for locking'said plate and said bearingtub'e 17, in varied adjusted positions, withm the cylindrical member 11. The cylindrical member 11, is also provided around its upper end with a ring or plate.

'moveupon the screw Rotatably seated at its lower end in the bearing box 10, is a main feed screw 25. Mounted on said screw near its upper end is a threaded sleeve, or long feed nut, 26, shown in section in Fig. 3, keyed to which is a gear 27. Mounted to turn loosely .on said feed nut 26, and one above the other, arebwo compound gears 28 and 29, each of which is a short shaft 33, provided on. its'outer end with a hand wheel 34, having ahandle 35. On its inner'end said shaft 33, is provided with-a gear 36, which meshes with the beveled gear 30, keyed tothe sleeve 26. Thus by operating the hand Wheel 34, the feed nut 26, can be rotated through the beveled gears 30 and 36, causing said sleeve 26, to 25, in either direction, as desired. 4

Mounted in a bearing portion32 of said topcasting 32, is -a driving shaft37, providednear its upper endwith a driving pulley 38. =Slidably mounted upon. the upper end, and keyed to said shaft 37, is clutch member 39, adapted to be moved by hand into and out'of interlocking engagement withtherpulley 38, said clutch member being,provided with a plurality of pins 39, adapted to be moved into sockets 38, in said pulley 38. Said clutch ,member isfrictionally held out of engagement with said pulley 38, b means of a spring-pressed ball 40, as clear y shown in Fig. 3. Mounted upon said driving shaft 37, is a pinion 41, which is keyed to said shaft by means of a pin 42.

. Said pinion 41, meshes with the gear 29, on

the threaded sleeve or longfeed nut 26, which moves on the screw 25. Loosely mounted on the shaft 37, is a compound gear 43, which meshes with the pinion has'a pinion portion designated, respectively portion 29, of the. gear 29, the pinion portion 43, of said compound gear 43, meshing with the gear 28. Also mounted loosely on said shaft 37, is a second compoundgear 44, which meshes with the pinion portion '28, of the gear 28. The pinion portion 44, of the gear 44, constitutes the driving pinion for a group of pinions 45, 46and 47, mounted. upon a supportirg member 48, on said shaft 37, and provided with a handle49, whereby said supporting member 48, can be turned on said shaft 37, 'to put either pinion 45, or inion 47, into mesh with the gear 27, whic is keyed to the threaded sleeve or nut 26, as at 27. By moving pinion 47, into mesh withsaid gear 27 said gears 27, is driven in one direction, and y moving the pinion 45, into mesh with said gear 27, said gear 27, is reversed and lso . driven in theopposite direction from the pinion".portion '44, of the by mov'ernentof the handle 49., in either digear 44. Thus 1 motion, the threaded sleeve, or feed nut 26,

Figs. 3 and 4.- Mounted upon the'lower i jend of said shaft 37, is .a fan element 50,

16 providediwith a pipe, or tube, 52, which extends downwardly into a position to blow can be driven in either direction from the shaft v 37, through thetrain of gears above described, as will be clearly understood from turning within a hopper-like member '51,

the grindings and dustfrom the grind-. 1ngelement20, and the upper end of the cylinder C, downwardly, into said cylinder C. Supported by the top casting 32, is a.

motor 53, the drive shaft 54.0fwh1ch is .provided with a driving pulley 55. Pivotally connected to the end of the top castin 32, is a lever 56,. upon one end of whic mounted a pulley 57, and the other end of which lever is connected by means of a spring 58, to the body portion of said top casting 32. Afbelt 59', extends around said pulley 5'7, and partially around. the pulley 55, of the motor, around the pulley 138, on the drive shaft 37, and around the pulley 19,

on thedriving spindle 18, and thence backto the pulley '57. The spring-controlled.

lever 56, which carries the pulley -57, oper-f ates automatically to keep the driving belt 59taut. I

Thus from the motor 53, the shaft 37, which carries the pulley 3'8, and the grinding spindle 18, which carries the pulley 19, .are directly driven at a high rate of speed.

' From the shaft 37, and its pinion 41, secured titi thereto, through the train of gears above described, said threaded sleeve, or feed nut, 26, is driven at a greatly reduced speed for moving said feed nut, and the main top casting 32, which. carries the cylinder member 11, the tubular member 17, and the grinding.

spindle 18, gradually downwardly, through the bearing sleeve portion 7, of the base casting 5,. thus providing for the feeding of the grinding element 20, longitudinally through the cylinder C, during its revolvingmovcment and its rotative movement. The gear ring 1f4, on the cylindrical member '11, is in A mesh with the gear 28, ofsaid; train of gears and is thus. driven at'a less speed than is the shaft 37, and the spindle 18, and at a greater speed than is the long feed nut 26." Through this drive, betweenthe gear 14 and the gear 28,, the cylindrical member- 11 is drivemrevolvingthe, tubular member 17, andgthe.

spindle '18, in sucha way that the grinding element 20-, l on the lower end of the spindle is carriedbodily. around theinne'r wall of -thefcylinder C, during its rotating moveinent, nd its feedmovement long tudinally through said cylinder.

As betoredescribed, the turningofthe tubular member 17, to different positions within the cylindrical melnber 11', regulates the throw or circular course of travel of said spindle and its driving element 20, thus maklng it possible to regulate the travel of said -grinding element so as to adapt it to cylinders of different diameters. By changing said grinding element for grinding elements of-diiferent diameters, a still further adap: .tation of said machine can be made for smaller or larger cylinders. Referring to Figs. 11 and 12, I will now describe the mechanism for adjusting the.

machine centrally over the cylinder C. The supporting frame 1, is placed on the top of the cylinder C. A centering device is then placed in the supporting frame 1, which J centering device comprises a round body casting 60, adapted to fit the central opening in the lower ring3, of said open frame 1, as clearly shown in said'Fig. 11. Mounted on the under side of said round bodymem ber 60, of said centering device, is a series of dependin supporting lugs 61-61 pivotally connectied to each of which is a bell crank lever 62, one end of. which is adapted to be swung outwardly against the inside of the cylinder C, while their other ends, or

arms, approach each other, as at 63,' Fig. 11, in a position to be engaged by the lower end of a screw 64, provided at its upper end Twithan operating. member, 65, whereby as said screw 64, is turned down through the body 60, it presses downwardly on the inner ends of said bell crank levers 62, forcing their lower arms outwardly together into bearing engagement with the inner wall of said cylinder C. This adjustment moves the frame 1, so that the central openings 44 in the open frame 1, is centered relative to the inside of the cylinder C. In this position said open frame 1, is firmly clamped onto the cylinder 0, in any desired manner, afterwhich the centering device 66, can be removed and the grindlng machine set thereupon, with its base plate 5, seated in the top ring 2, of said open frame 1, as clearly shown in Fig. 1.

Referring now to Figs. 7, 8, 9 and 10, we

will describe our invention as adapted for grinding pistons. A horizontal base 66, having a vertical wall member 67, with a central opening 67 therethrough, is provided, said base having an extension 68, upon whichis slidably mounted a tail-stock 69, having the spindle 70, with operating "hand wheel 71, and the center'pin 72,

its upper end, is supported upon a block 73,

at one end of the base 66, said guide bar 9 thus forming a track, or support, upon which the guide lug portion 13, of the main top 5 casing of the machine moves. Mounted upon the base 66, at one side, is a standard 74, provided at its upper end with a bearing box 75, to receive a shaft 76, which is suported at its opposite end in a similar bearmg box 77, formed as a part of the 'wall member 67, as will be understood from Fig. 7. Secured to said shaft 76, is a gear drum 78, so positioned that it will mesh ,WlthtllB gear ring 14.. On the cylindrical member 11, the opposite end of said shaft 7 6, is proyided with a holding block, or chock, 79, adapted to receive and hold and turn the piston P.

When our machine is thus used for grindin a piston, it will be evident that the revo ving movement of the c lindrical member 11, is not necessary. T erefore the key 15, which'locks the gear. ring 14, to said cylindrical member 11, is withdrawn so as to '25- permit said gear ring to turn upon sa d cylindrical member '11, as in Fig. 8.

' In order to prevent said cylindrical member 11 from turning, a set screw 80, is provided in the bearing casting 12, of the main top casting 32, whereby to secure said cylindrical member 11. against turning during the operation of the machine- As the machine is thus operated, the spindle 18, is driven or rotatedabout its axis and is fed longitudinally because of the drive from the shaft 37, through the train of gears to the j threaded sleeve, or feed nut, 26, the grinding-element 20, revolving at a high rate of speed and moving longitudinally along the piston P, said piston P being revolved through its shaft 76, running loose on the cylindrical member 11, and driven from the gear 28.

Attention is called to the fact that from one motor, or source of power, all of the necessary drivingconnections are made for driving the power shaft and the grinding element at a high rate of speed, and for feeding said grinding element slowly longitudinally through a cylinder, or along a iston, with means for revolving said grind- H1 element bodily around the inside of a cy inder, as hereinbefore described, together with means for locking said cylindrical member 11, whereby to prevent the bodily revolving movement of said grinding element when said machine is used for grindin apiston, as described.

e are aware that many changes can be 80 made in our invention as here embodied for purposes of illustration, without departing from the spirit thereof, and we do not, therefore, limit the invention to these details, except as we may be limited by the hereto 65 appended claims.

member and said driving-shaft at different speeds and for automatically moving said cylindrical member and said driving shaft longitudinally at a greatly reduced speed.

2. In a grinding machine of the character referred to, in combination, a cylindrical member rotatably and movably mounted, a tubular bearing member rotatably mounted eccentrically in said cylindrical member, a driving shaft rotatably mounted eccentrically through said tubular bearing member and provided at its end with a grinding element, a motor, driving connections front said motor for simultaneously rotating said cylindrical member and said driving shaft at different speeds, and for automatically moving said cylindrical member and said driving shaft longitudinally at a greatly reduced speed, and means for reversing, at will, the direction of the longitudinal movement of said cylindrical member and driving shaft.

3. In a grinding machine of the character referred. to, in combination, a cylindrical member rotatably and movably mounted, a

tubular bearing member rotatably mounted eccentrically in said cylindrical member, :1 L106 driving shaft rotatably mounted eccentrically through said tubular bearingmember and provided at its end with a grinding element, said driving shaft having its bearings in said tubular bearing member, a motor, 110 driving connections from-said motor for si multaneously rotating said cylindrical menu her and said driving shaft at different speeds and for automatically moving said cylindrical member and said driving shaft longitudinally at a greatly reduced speed, and means for manually moving said cylindrical member and said driving shaft longitudinally, in either direction, at will.

4. In a grinding machine of the character referred to, in combination, a cylindrical member rotatably and movably mounted, a

.tubular bearing member rotatably mounted eccentrically in said cylindrical member, a driving shaft rotatably mounted eccentri- 126 cally through said tubular bearing member and provided at its end with a grinding element, a motor, driving connections from said motor for simultaneously rotating said cylindrical member and said driving shaft at 130 1,sce,1ee I ing said cylindrical member and said driving shaft longitudinally at a greatly reduced speed, means for reversing, at will, the direction of the longitudinal movement of said i cylindrical member and driving shaft, and

means for manually moving said cylindrical member andsaid driving shaft longitudinally, in either direction, at will.

' 5. In a grinding machine of the character referred to, in combination," supporting means, a cylindrical member rotatably and movab'ly mounted therein, a tubular bearing member adjustably mounted eccentrically in saidcylindrical member, a grinding shaft rotatably mounted eccentrically through said tubular bearing member, said grinding shaft having bearings in said tubular beartill ing member, a grinding element thereon, a power shaft, a, motor, driving connections therefrom to said'power shaft and to said grinding shaft, gear connections from said power shaft to said cylindrical member for turning the same, and means driven from said ower shaft formoving said cylindrical mem er'and said grinding shaft longitudinally, substantially as described.

6. In a grinding machine of the character referred to, in combination, supporting,

means, a cylindrical member rotatably and movably mounted therein, a tubular bearing member adjustably mounted eccentrically in said cylindrical member, a grinding shaft rotatably mounted eccentrically through said tubular bearing member, a

grinding element thereon, a power shaft, a motor, driving connections therefrom to said power shaft and to said grinding shaft, gear connections from said power shaft to said cylindrical member for turning the same, and'means driven from said power shaft for moving said cylindrical member and said grinding shaft longitudinally, said means being, reversible at will, whereby to move said member and said shaft in either direction, substantially as described. 7

7. in a grinding machine, in combination, supporting means, a cylindrical member mounted to be rotated and moved longitudinally therein, a tubular bearing member mounted eccentrically in said cylindrical member, a grinding shaft rotatably mounted 'eccentrically through said tubular bearing member, a grinding element thereon, a power shaft, a screw, gear connections from said power shaft and said screw for rotating said cylindrical member and for moving the same longitudinally, a motor, and drivingconnections therefrom to said power shaft and to said grinding shaft, whereby said power shaft and said grinding shaft are driven direct from said motor, and said cylindrical member is revolved at a reduced speed from the gear connections from said power shaft and ismoved longitudinally by said screw and its connections, substantially as described.

8. In a grinding machine, in combination,

member, a grinding shaft rotatably mounted eccentric-ally through said tubular bearing member, a grinding element thereon, a

, power shaft, ascrew, gear connections from said power shaft and said screw for rotating said cylindrical member and for moving the same longitudinally, means for reversing the driving connections from said screw, whereby to reverse the direction of movement longitudinally of said cylindrical member, a motor, and driving connections therefrom to said power shaft and to said grinding shaft, whereby said power shaft and said grinding shaft are driven direct from said motor, and said cylindrical member is revolved at a reduced speed from the gear connections from said power shaft and is moved longitudinally by said screw and its connections, substantially as described;

9. In a grinding machine, in combination,

supporting means, a cylindrical member mounted to be rotated and moved longitudinally therein, a tubular bearing member mounted eccen-trically in said cylindrical "member, a grinding shaft rotatably mounted eccentrically through said tubular bearing member, a grinding element thereon, a power driven from said motor with means for di-" recting a current of air therefrom to the grinding element on said grinding shaft, substantially as described.

10. In a grinding machine, in combination, a supporting base, provided with a driving shaft having means for holding and revolving a piston, a grinding mechanism adapted to be mounted on said baseand comprising a cylindrical member mounted to be moved longitudinally, a grinding shaft rotatably mounted through said cylindrical member, a motor,;driving connections from said motor for driving said grinding shaft and for moving said cylindrical member longitudinally, and driving connections to said driving shaft, whereby said driving shaft and said'grinding shaft are rotated andsaid cylindrical member and said grind- 55 "shaft,-substantially-asshown and described.

v14 A grinding machine comprising in said base and comprising in combination a' ing shaft therein are moved longitudinally, substantially as described."

11.-In a grinding machine, in'combination, a supporting base provided with means for 'rotatably supporting a piston. a grinding mechanism adapted to be 'mbu'ntedon grinding shaft mounted to be adjusted bodily about an axis parallel and eccentric to its axis of rotation and to be revolved and moved longitudinally, a motor, driving connections from said motor for revolving scribed.

' ing said grinding shaft and said piston support means and for moving said grinding shaft longitudinally, and a grinding element on said grinding shaft, substantially as de- 12. In a grinding machine, in combination', a supporting base,'a driving shaft'protatably and adjustably "mounted eccentrivided with means for supporting and revolving a piston, a cylindrical member mounted to be revolved and to be moved longitudinally therein, a grinding shaft rocally therein, a grinding element thereon, a

motor, driving connections therefrom for 7 driving said driving shaft and. said grmding shaft and. for moving said cylindrical member and said grinding shaft longituditudinally, substantially as described.

13. A grinding "machine comprising in combination a supporting base provided with -.a driving shafthaving means for supportin and turningan article to be ground,

j a grin ing mechanism adapted to be detachably mounted thereupon and comprising in combination a cylindrical member, a tubular bearing member mounted eccentricall and adjustably therein, a grinding sha mounted eecentricallv through said tubular bearin member and provided with a grinding element adjacent the article to be ground, a motor,'driving connections thererom cal member, a gear ring on saidcylindrical member in mesh with the gears on said feed nut, driving connections from said motor" to said gears, wherebyto turn saidfeed nut on said screw and to rotate said cylindricalmember, means for locking said cylindrical member against rotation at will without interfering with its movement longitudinally,

and drlving connections to said driving combination a supporting base provided with a driving shaft having means for sup:

, portin and turning an article to be ground,

a grin ing mechanism'adapt'ed to be detach ably mounted thereupon and comprising in combination a cylindrical member, a tubular bearing member mountedeccentricall and adjustably therein, a grinding sha 'element adjacent the article to .be

to said grinding shaft. a screw with; feed nut thereon, gears on said feed nut, connections from said feed-nut to said cylindricylindrical member'at will, a bearing mounted eccentrically throughsaid tubular bearing member and provided with a-grinding, element adjacent the article to be ground, a motor, driving connections therefrom to said grinding shaft, a screw with feed nut thereon, gears on said feed nut, connections from said feed nut to said cylindrical member, a gear ring on said cylindrical member in mesh with the gears on said feed nut, driving connections from said motor to said gears, whereby to turn said feed nut on said screw and to rotate said cylindrical. member, means for reversing the driye to said feed nut, means for locking said cylindrical member against rotation at will without interfering with its movement longit'udinally, and driving connections to said a driving shaft, substantially as. shownand described. y

15. A grinding machine comprising in combination a supporting base provided with a driving shaft having means for sup porting and turning an article to be ground,

a grinding mechanism adapted to be detachably mounted thereupon and comprising in combination a cylindrical member, a tubular bearing member mounted eccentrically and adjustably therein, a grindin shaft mounted eccentri cally through said tubular hearing member and provided with a grindin oun a motor, driving connections there om td said grinding shaft, a screw with feed nut thereon, gears onsaid feed nut, connections from said feed nut to said cylindrical memher, a gear ring on said cylindrical member in mesh with the gears on said feed nut, means for locking said cylindrical member against rotation and for releasing the gearring to be driven loosely thereon. driving connections from said motor to said gears, wherebytoturn said feed nut on said screw and to rotate said cylindrical member,

means for-locking said cylindrical member against rotation at will without interfering with its movement longitudinally, and driving connections to said driving shaft, substantially as shown and described.

16. In a grinding machine, .in combination, asupporting base a driving shaft provided with a gear drum and means for supporting and turning an article to be ground,-

said feed nut, a power shaft provided with gears adapted to mesh with the gears on said feed nut, a motor, driving connections from said rnotor to said power shaft, substantially said motor to said power shaft and to said as described. a grinding shaft, gear connections from said Signed at Portland, Multnomah county, power shaft to said feed nutand to said Oregon, this 19th day of January, 1917.

5 gear ring on said cylindrical member, Wherev ALBERT B. cOMBs. b to turn sald feed nut and said cylindr cal I iriember, means for reversing the direction I FRf/XNK U G of drive of said nut at will, means for manu- In presence"of l ally turning said feed nut, and a clutch I. M. GRIFFIK,

10 mechanism for discennecting the drive from WARREN P. SMITH. 

